Safe Haskell | Safe |
---|---|
Language | Haskell2010 |
This module defines the TextualMonoid
class and several of its instances.
Synopsis
- class (IsString t, LeftReductive t, LeftGCDMonoid t, FactorialMonoid t) => TextualMonoid t where
- fromText :: Text -> t
- singleton :: Char -> t
- splitCharacterPrefix :: t -> Maybe (Char, t)
- characterPrefix :: t -> Maybe Char
- map :: (Char -> Char) -> t -> t
- concatMap :: (Char -> t) -> t -> t
- toString :: (t -> String) -> t -> String
- any :: (Char -> Bool) -> t -> Bool
- all :: (Char -> Bool) -> t -> Bool
- foldl :: (a -> t -> a) -> (a -> Char -> a) -> a -> t -> a
- foldl' :: (a -> t -> a) -> (a -> Char -> a) -> a -> t -> a
- foldr :: (t -> a -> a) -> (Char -> a -> a) -> a -> t -> a
- scanl :: (Char -> Char -> Char) -> Char -> t -> t
- scanl1 :: (Char -> Char -> Char) -> t -> t
- scanr :: (Char -> Char -> Char) -> Char -> t -> t
- scanr1 :: (Char -> Char -> Char) -> t -> t
- mapAccumL :: (a -> Char -> (a, Char)) -> a -> t -> (a, t)
- mapAccumR :: (a -> Char -> (a, Char)) -> a -> t -> (a, t)
- takeWhile :: (t -> Bool) -> (Char -> Bool) -> t -> t
- dropWhile :: (t -> Bool) -> (Char -> Bool) -> t -> t
- break :: (t -> Bool) -> (Char -> Bool) -> t -> (t, t)
- span :: (t -> Bool) -> (Char -> Bool) -> t -> (t, t)
- spanMaybe :: s -> (s -> t -> Maybe s) -> (s -> Char -> Maybe s) -> t -> (t, t, s)
- spanMaybe' :: s -> (s -> t -> Maybe s) -> (s -> Char -> Maybe s) -> t -> (t, t, s)
- split :: (Char -> Bool) -> t -> [t]
- find :: (Char -> Bool) -> t -> Maybe Char
- elem :: Char -> t -> Bool
- foldl_ :: (a -> Char -> a) -> a -> t -> a
- foldl_' :: (a -> Char -> a) -> a -> t -> a
- foldr_ :: (Char -> a -> a) -> a -> t -> a
- takeWhile_ :: Bool -> (Char -> Bool) -> t -> t
- dropWhile_ :: Bool -> (Char -> Bool) -> t -> t
- break_ :: Bool -> (Char -> Bool) -> t -> (t, t)
- span_ :: Bool -> (Char -> Bool) -> t -> (t, t)
- spanMaybe_ :: s -> (s -> Char -> Maybe s) -> t -> (t, t, s)
- spanMaybe_' :: s -> (s -> Char -> Maybe s) -> t -> (t, t, s)
Documentation
class (IsString t, LeftReductive t, LeftGCDMonoid t, FactorialMonoid t) => TextualMonoid t where Source #
The TextualMonoid
class is an extension of FactorialMonoid
specialized for monoids that can contain
characters. Its methods are generally equivalent to their namesake functions from Data.List and Data.Text, and
they satisfy the following laws:
unfoldr splitCharacterPrefix . fromString == id splitCharacterPrefix . primePrefix == fmap (\(c, t)-> (c, mempty)) . splitCharacterPrefix map f . fromString == fromString . List.map f concatMap (fromString . f) . fromString == fromString . List.concatMap f foldl ft fc a . fromString == List.foldl fc a foldr ft fc a . fromString == List.foldr fc a foldl' ft fc a . fromString == List.foldl' fc a scanl f c . fromString == fromString . List.scanl f c scanr f c . fromString == fromString . List.scanr f c mapAccumL f a . fromString == fmap fromString . List.mapAccumL f a mapAccumL f a . fromString == fmap fromString . List.mapAccumL f a takeWhile pt pc . fromString == fromString . takeWhile pc dropWhile pt pc . fromString == fromString . dropWhile pc mconcat . intersperse (singleton c) . split (== c) == id find p . fromString == List.find p elem c . fromString == List.elem c
A TextualMonoid
may contain non-character data insterspersed between its characters. Every class method that
returns a modified TextualMonoid
instance generally preserves this non-character data. Methods like foldr
can
access both the non-character and character data and expect two arguments for the two purposes. For each of these
methods there is also a simplified version with underscore in name (like foldr_
) that ignores the non-character
data.
All of the following expressions are identities:
map id concatMap singleton foldl (<>) (\a c-> a <> singleton c) mempty foldr (<>) ((<>) . singleton) mempty foldl' (<>) (\a c-> a <> singleton c) mempty scanl1 (const id) scanr1 const uncurry (mapAccumL (,)) uncurry (mapAccumR (,)) takeWhile (const True) (const True) dropWhile (const False) (const False) toString undefined . fromString
fromText :: Text -> t Source #
Contructs a new data type instance Like fromString
, but from a Text
input instead of String
.
fromText == fromString . Text.unpack
singleton :: Char -> t Source #
Creates a prime monoid containing a single character.
singleton c == fromString [c]
splitCharacterPrefix :: t -> Maybe (Char, t) Source #
Specialized version of splitPrimePrefix
. Every prime factor of a textual monoid must consist of a
single character or no character at all.
characterPrefix :: t -> Maybe Char Source #
Extracts a single character that prefixes the monoid, if the monoid begins with a character. Otherwise returns
Nothing
.
characterPrefix == fmap fst . splitCharacterPrefix
map :: (Char -> Char) -> t -> t Source #
Equivalent to map
from Data.List with a Char -> Char
function. Preserves all non-character data.
map f == concatMap (singleton . f)
concatMap :: (Char -> t) -> t -> t Source #
Equivalent to concatMap
from Data.List with a Char -> String
function. Preserves all non-character
data.
toString :: (t -> String) -> t -> String Source #
Returns the list of characters the monoid contains, once the argument function converts all its non-character factors into characters.
any :: (Char -> Bool) -> t -> Bool Source #
all :: (Char -> Bool) -> t -> Bool Source #
foldl :: (a -> t -> a) -> (a -> Char -> a) -> a -> t -> a Source #
The first argument folds over the non-character prime factors, the second over characters. Otherwise equivalent
to foldl
from Data.List.
foldl' :: (a -> t -> a) -> (a -> Char -> a) -> a -> t -> a Source #
Strict version of foldl
.
foldr :: (t -> a -> a) -> (Char -> a -> a) -> a -> t -> a Source #
The first argument folds over the non-character prime factors, the second over characters. Otherwise equivalent to 'List.foldl\'' from Data.List.
scanl :: (Char -> Char -> Char) -> Char -> t -> t Source #
scanl1 :: (Char -> Char -> Char) -> t -> t Source #
Equivalent to scanl1
from Data.List when applied to a String
, but preserves all non-character data.
scanl f c == scanl1 f . (singleton c <>)
scanr :: (Char -> Char -> Char) -> Char -> t -> t Source #
scanr1 :: (Char -> Char -> Char) -> t -> t Source #
Equivalent to scanr1
from Data.List when applied to a String
, but preserves all non-character data.
scanr f c == scanr1 f . (<> singleton c)
mapAccumL :: (a -> Char -> (a, Char)) -> a -> t -> (a, t) Source #
Equivalent to mapAccumL
from Data.List when applied to a String
, but preserves all non-character
data.
mapAccumR :: (a -> Char -> (a, Char)) -> a -> t -> (a, t) Source #
Equivalent to mapAccumR
from Data.List when applied to a String
, but preserves all non-character
data.
takeWhile :: (t -> Bool) -> (Char -> Bool) -> t -> t Source #
The first predicate tests the non-character data, the second one the characters. Otherwise equivalent to
takeWhile
from Data.List when applied to a String
.
dropWhile :: (t -> Bool) -> (Char -> Bool) -> t -> t Source #
The first predicate tests the non-character data, the second one the characters. Otherwise equivalent to
dropWhile
from Data.List when applied to a String
.
break :: (t -> Bool) -> (Char -> Bool) -> t -> (t, t) Source #
'break pt pc' is equivalent to span (not . pt) (not . pc)
.
span :: (t -> Bool) -> (Char -> Bool) -> t -> (t, t) Source #
'span pt pc t' is equivalent to (takeWhile pt pc t, dropWhile pt pc t)
.
spanMaybe :: s -> (s -> t -> Maybe s) -> (s -> Char -> Maybe s) -> t -> (t, t, s) Source #
spanMaybe' :: s -> (s -> t -> Maybe s) -> (s -> Char -> Maybe s) -> t -> (t, t, s) Source #
Strict version of spanMaybe
.
split :: (Char -> Bool) -> t -> [t] Source #
Splits the monoid into components delimited by character separators satisfying the given predicate. The characters satisfying the predicate are not a part of the result.
split p == Factorial.split (maybe False p . characterPrefix)
find :: (Char -> Bool) -> t -> Maybe Char Source #
elem :: Char -> t -> Bool Source #
foldl_ :: (a -> Char -> a) -> a -> t -> a Source #
foldl_ = foldl const
foldl_' :: (a -> Char -> a) -> a -> t -> a Source #
foldr_ :: (Char -> a -> a) -> a -> t -> a Source #
takeWhile_ :: Bool -> (Char -> Bool) -> t -> t Source #
takeWhile_ = takeWhile . const
dropWhile_ :: Bool -> (Char -> Bool) -> t -> t Source #
dropWhile_ = dropWhile . const
break_ :: Bool -> (Char -> Bool) -> t -> (t, t) Source #
break_ = break . const
span_ :: Bool -> (Char -> Bool) -> t -> (t, t) Source #
span_ = span . const
spanMaybe_ :: s -> (s -> Char -> Maybe s) -> t -> (t, t, s) Source #
spanMaybe_ s = spanMaybe s (const . Just)
spanMaybe_' :: s -> (s -> Char -> Maybe s) -> t -> (t, t, s) Source #